Several studies have shown that physical and/or sexual abuse during childhood may lead to the development of obesity later in life. Despite these consistent findings, the mechanism for the increased risk of obesity following developmental trauma is unknown. It has been suggested that psychological dysfunction, including the presence of disordered eating behavior, may account for the added risk of adult obesity. To test this hypothesis, we analyzed the prevalence and severity of different types of early traumatic life events, assessed the presence of co-existing psychiatric disorders and measured adult attachment style in a sample of 200 subjects including non-obese healthy volunteers and obese participants undergoing a psychiatric assessment to determine suitability for bariatric surgery. Participants who scored higher on a scale measuring the severity of traumatic events experienced during the first 15years of their lives were more likely to be obese at the time of testing. The exclusion of the participants who experienced physical and/or sexual abuse did not change the results of statistical analysis. Severity of early trauma remained a significant predictor of adult obesity when the influence of psychiatric diagnosis and anxious attachment was taken into account. These findings suggest that: (1) not only sexual or physical abuse but also less severe forms of early-life stress are linked to the development of obesity later in life; and (2) psychological dysfunction is not the only mechanism mediating the elevated risk of obesity in persons exposed to early-life trauma.